1. Field of the Invention
The present invention relates to an instrument to measure leakage of steam from a steam trap which determines the operational status of the trap, e.g., if the steam is leaking or not, or which measures the leakage rate of steam.
2. Description of the Prior Art
A steam trap is a device attached to a steam pipeline or to equipment using steam and which automatically discharges only the condensed water without leaking out steam. Since leakage of steam must be monitored more strictly with increasing fuel cost, avoiding leakage of steam becomes more of a prerequisite in adopting a steam trap. After completion of the piping, steam traps are strictly monitored for steam leakage and those leaking steam are repaired or replaced.
Various leakage measuring instruments for steam traps have thus far been developed and actually used.
One type of instrument provides a through-vision window in the outlet piping of the steam trap to visually check the condition of flow inside the pipe. Other types applying a thermometer or vibration meter have been used to measure the surface temperature of the steam trap or the sound of fluid flow. However, neither of these methods were able to observe the condition of leakage qualitatively and they were not able to measure the leakage amount quantitatively. Therefore, it was necessary that the extent of the leakage be judged only by relying on human observation.
Therefore, applicant has developed a simple instrument to measure leakage of steam from a steam trap which is disclosed in Japanese Patent Application No. 56521 of 1986. This instrument is to be arranged between the steam supply side and the steam trap and measures the quantity of steam leakage based upon the interrelationship between the steam quantity passing the orifice and the water level at the primary side.
The foregoing instrument, however, presents a problem in that an accurate measurement of steam leakage is impossible because water level before and after the orifice changes with the quantity of condensed water flow in the measuring equipment and also the water level of the primary side of the orifice ripples.